Currently deployment plans are coupled to build plans, and environments are contained in deployment plans.
This doesn't allow sharing of environments between build/deployment plans. For example some QA setup may be used by two different projects.

It would be better if Bamboo would allow storing information about an environment and its "targets" (could be a server, CDN, WEBDAV, ...). Every target will have steps which take an input artifact and make sure it is deployed on that target.
A deployment plan would then be a mapping between artifacts and a deployment environment, allowing sharing of environments.